Jim -<P>The WT-110A is a good tester. It uses mutual conductance for the quality test, and setup is, of course, very convenient.<P>The meter has Renew-?-Good on the scale. Some people would prefer a scale marked in micromhos. (The meter does have a second scale reading from 0-10, but it's just not the same thing.)<P>You will need to buy or make a socket adapter to test 4, 5 and 6 pin tubes, or older 7 pin tubes. Test card data is available for a number of these old tubes.<P>You'll probably find it easier to get test card data than the test cards themselves. That's OK since it's easy to make up your own cards from the data.<P>------------------<BR>Bill Frank

Jim -<P>There is a master punch card that has all holes punched out. You look up in the test card data sheets what holes need to be punched to automate the testing of a particular tube, use the master card to draw circles in the correct locations on a blank card, and use a standard single-hole punch to punch the holes in the blank card.<P>If the WT-110A you are looking to purchase doesn't come with a master card, try to bargain the price down because of the hassle of conjuring up a replacement. I can scan my master card and send you a jpg or gif file, but you'll have to take the time to do a precision job of punching out all the holes.<P>It's not so much of a problem if there is no hole puncher or blank cards. Exactly the same style hole puncher can still be purchased at a number of office supply stores, and blank cards can be cut out from sheet plastic of the same thickness as the originals.<P>RCA sold adapters for testing older style tubes on the WT-110A, and similar adapters from other companies like Jackson or Hickok would probably work. Good luck finding one.<P>You can make up adapters by wiring a socket for an older style tube to a base with a pin configuration that matches one of the sockets on the WT-110A. You might be able to find used or New Old Stock sockets and bases from places like Play Things Of Past <A HREF="http://www.oldradioparts.com/" TARGET=_blank>http://www.oldradioparts.com/</A> or you could scrounge sockets from junker chassis and bust up dead tubes for their bases (watch out!).<P>As for which pin receptors on the socket to wire to which pins on the base, I'd have to do some research to figure it out. The documentation I got with my Jackson 658A has a pinout for their PIP adapter, which I haven't actually used with my WT-110A yet but it looks like it should work.<P>------------------<BR>Bill Frank

Jim<P>The WT-110A is a good tester.<BR>If they have not been replaced the<BR>7 cap's and 4 selenium rectifier's need<BR>to be replaced. But the WT-110A is one<BR>of few tester that has how to calibrate<BR>it in the manual. The WG-337A tube socket adapter set is for 4.5,6, and 7 pin tubes, they plug into the octal socket. But the<BR>adapter are wire pin 1 to pin 1, 2 to 2,<BR>etc. Supplement No.2 has some of the old<BR>tubes. I have the manual and have most of data plus there is a manual on BAMA <A HREF="http://bama.sbc.edu/" TARGET=_blank>http://bama.sbc.edu/</A> <P>Jimmie <P>------------------<BR>

Thanks, Jimmie. I have been looking for that manual for a while. But, and I hate to appear ungrateful, how the heck do I open the '.djvu' file? I have tried Acrobat, Word, a few others, and cannot open the file. Help?<BR>My 'secret' for getting my WT110-A going to peak level (even without a manual) is that there is a silenium rectifier and filter capacitor hidden underneath the chassis! You have to remove the chassis completely from the box to see them.

Randy<P>You need to download the DJVU plugin and install it in your browser, see: <A HREF="http://bama.sbc.edu/viewers.htm" TARGET=_blank>http://bama.sbc.edu/viewers.htm</A> <P>If you have a problem email me an I will<BR>send you a copy in PDF <P>Jimmie<BR> <P>------------------<BR>

Geez, is this the cat's pajamas, or what? Now I know how to calibrate the darn thing. Out it comes from under the pile, and on to the bench. Thanks yet again, Mr. Stewart. Your assistance is greatly appreciated.<P>------------------<BR>

Well, I bought the tester on ebay a few weeks ago. Seems to be in good shape. Jimmie, you said to replace the (4) selenium rectifiers. According to the parts list, there are (2) different values on the rectifiers - can I use 1N4007's for all four?<BR>Thanks,<BR>Jim<BR><P>------------------<BR>

I say you can, but the voltages will be a little higher. In some cases I like this (it simulates 'working voltages' a little better), and in some cases this is not such a good thing. You could put a resistor in series with the diode to drop a few volts. If you have an old NTE semiconductor guide, you can look up the rectifier and get the ratings. Or, just use 1N4007's, although it is a little overkill. Some folks know the color code for seleniums, but I sure don't.<P>------------------<BR>

Diodes are so cheap, you might as well use 4007s (or 5399s) for everything. But you'd probably find, if you measured some 4002s, that they are good to 1500PRV anyway. They all come off the same line. Overkill? That's the bag of 5408s I got for free: 3 amp 1000PRV.<P>------------------<BR>

Alan, the tester has (2) different selenium rectifiers:<BR>1: 130v, 65ma<BR>2: 20v, 75ma<BR>Is it still OK to use the 1N4007's (with the much higher PRV than the seleniums), or should I use diodes closer to the rated voltage and amps? I guess that I don't fully understand how diodes work, and their application to different circuits.<BR>Thanks,<BR>Jim<P> <P>------------------<BR>

As long as the replacement has a higher rating than the original, you're fine. The 20V selenium probably has only one plate, so it would have a lower forward voltage drop. If you replace that one with sillycon, you won't even need an extra surge resistor.<P>------------------<BR>

Hi Jim!<BR>I will leave it to Alan to respond to your question about the surge resistor (and/or voltage dropping resistor) for your 130v selenium--he has a lot more knowledge than me on this subject.<P>On this subject of diode/resistor combinations for replacing selenium rectifiers, I posted a question in this Forum on this subject a few weeks ago and got a lot of great responses. I really learned a lot, both in terms of theory and practical application. You can read it at:<BR> <A HREF="http://168.103.222.44/forums/Forum3/HTML/004540.html" TARGET=_blank>http://168.103.222.44/forums/Forum3/HTML/004540.html</A> <P>------------------<BR>Poston